Numerous commercial products incorporate material that has undergone processing in the form of a web of indefinite length material during some stage of its manufacture. When such webs are being processed, it is frequently desirable to divert the web to a different direction, or to invert the web so the opposite side of the web is facing upwards to receive, e.g., the application of a coating. For many applications it is conventional to wrap the web partially around one or more non-rotating air flotation devices called “air bars” or “air turns” in order to divert or invert the web. However, in some circumstances the use of an air bar is inconvenient. For example the web may be too heavy, too porous, or too textured for the needed air cushion to develop. In such circumstances, it is known that apparatuses that have, e.g., guide rotors disposed in spiral curves may be employed. However, these alternatives are bulky and complicated to construct.
Co-pending and coassigned U.S. patent application Ser. No. 10/676,188, “Apparatus For Deflecting or Inverting Moving Webs,” discloses a slat roller with a roller body having a longitudinal axis. A plurality of slats are mounted on a circumference of the roller body in such a fashion that the slats may translate from a first position in a direction parallel to the longitudinal axis of the roller body. While this is effective for diverting or inverting webs that cannot use an air turn, the slats on this slat roller must reverse direction twice per revolution to travel from a starting position to a translated position, then return. This requirement places a practical limit on the ultimate web speed that the roll can deal with. Further, this slat roller operates best when the wrap angle of the web with respect to the roller is 180 degrees or less.